Researchers Build Profile of the Drowsy Trucker

Among truck drivers, the practice of driving with a critical lack of sleep is an open secret. The transgression captured public attention earlier this month amid news of a New Jersey Turnpike accident that critically injured actor Tracy Morgan and killed comedian James McNair. Prosecutors say the Walmart truck driver, whose tractor-trailer plowed into the van shuttling the entertainers, had not slept in more than 24 hours.

Health and behavioral researchers worldwide have uncovered the prevalence of sleep-deprived driving among truckers and commercial vehicle operators. A recent Australian study highlighted some of the key demographic and behavioral differences between truck drivers who stay alert and those who nod off while on the road. The findings suggest that haulers aren’t really aware of the severity of their sleep deficits, and are also less prone to taking breaks during their driving stints.

Using police records, a multidisciplinary team of that included epidemiologists, sleep experts, and behavioral scientists tracked down and interviewed 530 heavy-vehicle drivers who had been involved in a crash between December 2008 and May 2011. Although none of those accidents involved fatalities, 24% of them resulted in at least one person being hospitalized.

The drivers were asked about the characteristics of their trucks, as well as their driving histories, sleep patterns, health behaviors, and substance use.  They were also asked to provide details of the crash, including time of occurrence and contributing factors.

For comparison purposes, the researchers conducted random interviews at truck stops, collecting responses from more than 500 truckers who had no involvement in accidents within the previous year.
Afterward, all the participants were invited to use a nasal flow monitor at home, which allowed the scientists to detect the presence of obstructional sleep apnea, a disorder that can severely disrupt the quality of one’s rest.

In looking over the data, the researchers found that drivers tended to work an average of 11 hours per day. The results also showed a relatively high rate of obesity, tobacco use, and sleep apnea compared to the general male population. But there were some key differences between the truckers who had been in recent crashes and those who hadn’t.  For one, the  truckers who had been involved in the accidents tended to have less driving experience. And findings related to sleep, health, work habits, and substance use were particularly revealing. Compared to the drivers interviewed at truck stops, those identified in police accident reports:

• had generally driven fewer hours and shorter distances over the previous week, but were more likely to have reported taking no breaks;
• were less likely to use caffeine, drink alcohol, smoke cigarettes, and to be obese; and
• on average, reported less sleep overall, but were less likely to report feeling sleep-deprived.

Other risk factors identified in the study included starting the trip between 6 p.m. and midnight, not using cruise control, and lacking an anti-lock braking system in the truck.

Alarmingly, the data recorded from the nasal flow monitors showed a high rate of sleep apnea among all the truckers interviewed, but only 4% reported having been diagnosed with the condition. (Those who tested positive for the disorder were contacted about getting medical help.) The scientists say this finding builds in other research showing that people most beset by chronic tiredness may also be the least aware of it.

Stevenson and his team acknowledge some limitations of the study, including the fact that the participants might avoid disclosing certain behaviors—especially those they fear are unlawful—and could have faulty memories about details of their accidents. Still, they recommend that commercial transport officials try to better understand and manage sleep apnea among haulers. The findings also show that scheduling drivers to take more breaks could drastically reduce road accidents.